It's one of the most beneficial things you can do to thicken, green, and revitalize your lawn. Kevin Frank, Michigan State University Extension, Department of Crop & Soil Sciences, had this to say:
"The spring rollercoaster of wet and dry conditions continues to persist across much of Michigan. For those areas that received a nice dumping of rain this last week, you may notice that in poorly drained areas where the soil may be staying saturated for several days, the turf may be looking a little brownish or yellow...one of the main reasons is impairment of the root system. It doesn’t take long once the soil is saturated for soil oxygen levels to decline and root hairs to begin to die. As the turf’s root system becomes impaired nutrient extraction and water uptake will be limited and the turf won’t look emerald green anymore. One simple practice that can help the turf in these areas...is core aeration."